Patients with chronic occlusive arterial disease due to atherosclerosis are often asymptomatic at rest but experience pain during exercise. Intermittent claudication indicates skeletal muscle blood flow insufficient to meet increases in metabolic demand. Cilostazol is a potent inhibitor of platelet aggregation which also possesses some vasodilating properties. This trial seeks to assess the safety and efficacy of chronic administration of cilostazol in these patients.